Recently, a new assay for LTBI has been developed, which evaluates interferon (IFN) -γ release by memory effector T-cells stimulated in vitro with specific mycobacterial antigens, ESAT-6 (early secretory antigen target-6) and CFP-10 (culture filtrate protein-10) [9-10]. The QuantiFeron -TB Gold test (QFT-G) uses ELISA to measure IFN-γ concentrations in supernatants in plate format and "In tube" format (QFT-GIT) while the enzyme-linked immunospot (ELISPOT) detects individual IFN-γ producing T-cells (TS-TB, Oxford Immunotech, Abingdon, UK).